This is why Caddy has config adapters: bring any config file language you like, and Caddy will run it. It's built-into the binary and just takes a command line flag to switch languages: https://caddyserver.com/docs/config-adapters

This makes it difficult to configure Caddy in anything except the native Caddyfile language due to a lack of thorough documentation. It's an interesting idea, but configuring Caddy with a yaml config that someone prior deemed a great idea was quite painful.

Curiously, LLMs have made it a lot easier. One step away from an English adapter that routes through an LLM to generate the config.

those formats aren't bijective with each other, right? so there's no way for you to say that foo.cue can be equivalently transformed to any foo.json or any foo.nginx or whatever representation, because those transformations are necessarily lossy, no?